Medical balloon including pleats

ABSTRACT

A balloon for a balloon catheter includes a body section and cone sections. At least one of the cone sections defines a plurality of grooves spaced around the circumference of the cone section.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. ProvisionalApplication Nos. 62/013,219, filed Jun. 17, 2014, and 62/137,897, filedMar. 25, 2015, the entirety of each of which is incorporated byreference.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a medical balloon includingpleats on at least a cone section of the balloon, and a method offorming the same.

BACKGROUND OF THE DISCLOSURE

Balloons mounted on the distal ends of catheters are widely used inmedical treatment. The balloon may be used to widen a vessel into whichthe catheter is inserted, open a blocked vessel and/or deliver a medicaldevice to a body location among other uses. The medical balloon includesa central body section, which is typically tubular, opposite conesections at opposite longitudinal ends of the body section, and oppositewaist sections at opposite longitudinal ends of the balloon. In use, theuninflated balloon is delivered to a treatment location within a bodylumen (e.g., a blood vessel) by tracking through an introducer sheathand exiting a distal end of the sheath to reach the treatment location.Once the uninflated balloon has reached the treatment location, fluid isdelivered into the balloon, thereby expanding the outer circumference ofthe balloon (i.e., balloon is inflated). After treatment, the balloon isdeflated and “pulled back” into the introducer sheath. The ballooncatheter can then be withdrawn from the introducer sheath and thepatient's body. It may be necessary or desired to re-introduce theballoon catheter into a body lumen, through the introducer sheath, tofurther treat the body lumen.

One known method of forming a medical balloon involves blow molding. Inparticular, the balloon is formed by radially expanding a segment ofextruded polymer tubing, called a parison, in a mold. Balloons producedby radially expanding a parison typically have thicker waist sectionsand cone sections than the thickness of their body sections. The thickercone sections may interfere with refolding of the balloon upon deflation(i.e., after treatment), which can make it difficult to pull the balloonback into the introducer sheath. This interference with re-folding mayalso make it difficult for the user to re-introduce the deflated ballooninto the sheath after withdrawing the balloon catheter from thepatient's body.

SUMMARY OF THE DISCLOSURE

In one example, a balloon for a balloon catheter includes a body sectionand cone sections. At least one of the cone sections defines a pluralityof pleats spaced around a circumference of the cone section. Each pleathas a length extending generally lengthwise of the cone section, a depthextending inward from an exterior surface of the cone section, and awidth extending circumferentially of the cone section.

Other features will be in part apparent and in part pointed outhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective of one embodiment of a medical balloon for aballoon catheter;

FIG. 2 is a fragmentary perspective of a balloon catheter including theballoon of FIG. 1;

FIG. 3 is an enlarged, fragmentary side elevational view of the balloonof FIG. 1, showing a distal cone section, a portion of a distal waistsection, and a portion of the body section thereof;

FIG. 4 is an enlarged, fragmentary section of the balloon taken alongthe line 4-4 in FIG. 3;

FIG. 5 is an enlarged, fragmentary section of the balloon taken alongthe line 5-5 in FIG. 3;

FIG. 6 is an enlarged section of the balloon taken along the line 6-6 inFIG. 3;

FIG. 7 is an enlarged, fragmentary section of the balloon taken alongthe line 7-7 in FIG. 3;

FIG. 8 is an enlarged, fragmentary section of the balloon taken alongthe line 8-8 in FIG. 3;

FIG. 9 is an enlarged, fragmentary section of the balloon taken alongthe line 9-9 in FIG. 3;

FIG. 10 is an enlarged, fragmentary section of the balloon taken alongthe line 10-10 in FIG. 3;

FIG. 11 is a schematic perspective of one embodiment of a blow mold foruse in forming a balloon;

FIG. 12 is a front elevational view of cone-waist molding section of theblow mold;

FIG. 13 is a longitudinal section of the cone-waist molding section;

FIG. 14 is an enlarged, partial view of FIG. 13;

FIG. 15 is a chart depicting data collected during pull-back forcetesting of test balloons and control balloons;

FIG. 16 is similar to FIG. 15, with data outliers removed therefrom;

FIG. 17 is a chart depicting data collected during re-insertion forcetesting of test balloons and control balloons

FIG. 18 is a perspective of another embodiment of a medical balloon fora balloon catheter;

FIG. 19 is an enlarged, fragmentary side elevational view of the balloonof FIG. 18, showing a distal cone section, a portion of a distal waistsection, and a portion of the body section thereof;

FIG. 20 is an enlarged, fragmentary section of the balloon taken alongthe line 20-20 in FIG. 19;

FIG. 21 is an enlarged section of the balloon taken along the line 21-21in FIG. 19;

FIG. 22 is an enlarged, fragmentary section of the balloon taken alongthe line 22-22 in FIG. 19

FIG. 23 is an enlarged, fragmentary section of the balloon taken alongthe line 23-23 in FIG. 19;

FIG. 24 is an enlarged, fragmentary section of the balloon taken alongthe line 24-24 in FIG. 19;

FIG. 25 is an enlarged, fragmentary section of the balloon taken alongthe line 25-25 in FIG. 19;

FIG. 26 is a schematic perspective of another embodiment of a blow moldfor use in forming a balloon;

FIG. 27 is a front elevational view of a cone-waist molding section ofthe blow mold in FIG. 26;

FIG. 28 is a longitudinal section of the cone-waist molding section inFIG. 27;

FIG. 29 is an enlarged, partial view of FIG. 28;

FIG. 30 is a perspective of another embodiment of a medical balloon fora balloon catheter, similar to the first embodiment;

FIG. 31 is an enlarged, fragmentary side elevational view of the balloonof FIG. 30, showing a distal cone section, a portion of a distal waistsection, and a portion of the body section thereof; and

FIG. 32 is longitudinal section of a cone-waist molding section forforming a portion of the medical balloon.

Corresponding reference characters indicate corresponding partsthroughout the drawings.

DETAILED DESCRIPTION OF THE DISCLOSURE

Referring to FIG. 1, one embodiment of a medical balloon for a medicaldevice is generally indicated at reference numeral 12 in FIG. 1. Theballoon defines an interior chamber 14 for receiving fluid therein toexpand an outer circumference (i.e., an outer periphery) of the balloon.The balloon 12 is shown in its expanded or inflated configurationthroughout the drawings, with the understanding that in its uninflatedand deflated configurations, the balloon is capable of foldinglengthwise such that the outer circumference of the balloon in itsuninflated and deflated configurations is substantially less than theouter circumference of the balloon in its expanded configuration. Withrespect to any or all of the below described embodiments of the presentdisclosure, the medical balloon 12 may be secured to a catheter,generally indicated at 16 in FIG. 2, such that a catheter body 18 of thecatheter extends axially through the interior chamber 14 of the balloon,as is generally known in the art, to form a balloon catheter, generallyindicated at 20. The balloon 12 and catheter body 18 have suitableshapes and dimensions for introduction into a desired body lumen fortreatment therein. Typically, the balloon 12, in its uninflated initialconfiguration, is introduced into the body lumen using an introducersheath (not shown). The uninflated balloon 12 is delivered to atreatment location within a body lumen (e.g., a blood vessel) bytracking through the introducer sheath and ultimately exiting a distalend of the sheath to reach the treatment location. Once the uninflatedballoon 12 has reached the treatment location, fluid is delivered intothe balloon, thereby expanding the outer circumference of the balloon(i.e., balloon is inflated). After treatment, the balloon 12 is deflatedand “pulled back” into the introducer sheath. The balloon catheter 20can then be withdrawn from the introducer sheath and the patient's body.It may be necessary or desired to re-introduce the balloon catheter 20into a body lumen, through the introducer sheath, to further treat thebody lumen.

The illustrated balloon catheter 20 may be configured for introductionalong and inflation (i.e., circumferential or peripheral expansion)within a blood vessel for treating vascular stenosis. As an example, themedical balloon 12 of the illustrated balloon catheter 20 may beconfigured for introduction along and inflation within one or more ofperipheral arteries and veins, coronary arteries and veins, renalarteries and veins, cerebral arteries and veins, and carotid artery. Inother examples, the medical balloon 12 may be configured forintroduction along and inflation within other body lumens for treatingstenosis of those lumens. The balloon 12 may be configured for treatingother body lumens and/or for other treatments of those lumens.

Referring to FIG. 1, the medical balloon 12 has a length L1 andcomprises a balloon body section 24; opposite proximal and distal waistsections 26 a, 26 b, respectively, at opposite longitudinal ends of theballoon; and opposite proximal and distal cone sections, generallyindicated at 28 a, 28 b, respectively, at corresponding proximal anddistal ends of the body section intermediate the body section and thecorresponding proximal and distal waist sections. As explained in moredetail below, the body section 24, waist sections 26 a, 26 b, and conesections 28 a, 28 b may be integrally formed during a blow moldingprocess to form the balloon 12 as a one-piece construction. It isunderstood that the balloon 12 may have other sections, structures,and/or components without departing from the scope of the presentinvention.

The balloon 12 may be formed from a polymer material, including, but notlimited to, a thermoplastic polymer or a thermoplastic elastomerpolymer. For example, suitable materials for the balloon includepolyesters such as PET, PEN and PBT; polyurethane block copolymers suchas ISOPLAST 301, PELLETHANE 2363-75D; polyamide block copolymers such asPEBAX 6333, PEBAX 7033 and PEBAX 7233; polyamides such as nylon 12,nylon 11, and nylon 10; polymer blend materials such as single ormultiphase blends of liquid crystal polymers in another polymer; andpolyester elastomer balloons such as ARNITEL EM 740 and HYTREL 8238.Other materials do not depart from the scope of the present invention asdefined by the claims. In one example, the balloon 12 may be free from alubricious coating (hydrophobic or hydrophilic), although in otherexamples the balloon may include such a lubricious coating.

As shown in FIG. 1, the body section 24 interconnects and is disposedbetween the distal and proximal cone sections 28 a, 28 b. In theillustrated embodiment, the body section 24 is generally tubulardefining a portion of the interior chamber 14 for receiving fluid toexpand an outer circumference (i.e., an outer dimension) of the bodysection. Referring to FIG. 3, the body section 24 has an expanded innerdiameter ID1 (i.e., an inner cross-sectional dimension) defined by aninterior surface 30 of the balloon 12, an expanded outer diameter OD1,and a thickness T1 that may be generally uniform along its length L1. Inone example, the expanded outer diameter OD1 may measure greater thanabout 3 mm, and in one example, from about 3 mm to about 30 mm, thesingle-wall thickness T1 may measure from about 0.0005 in (0.0127 mm) toabout 0.003 in (0.0762 mm), and the length L1 of the balloon may measureabout 10 mm to about 250 mm. The body section 24 may have other shapesand dimensions without departing from the scope of the presentinvention.

The distal and proximal waist sections 26 a, 26 b are generally tubularand, in the illustrated embodiment, are configured to receive thecatheter body 18 therein. Referring to FIG. 3, each waist section 26 a,26 b has an outer diameter OD2 less than the outer diameter OD1 of thebody section 24. Thicknesses T2 of the waist sections 26 a, 26 b may begreater than the thickness T1 of the body section 24. It is understoodthat the waist sections 26 a, 26 b may be omitted from the balloon 12without departing from the scope of the present invention.

In general, the distal and proximal cone sections 28 ab, 28 b are mirrorimages of one another. For purposes of this disclosure, the proximalcone section 28 b is shown in detail in the drawings, with theunderstanding that the teachings relating to the proximal cone sectionapply equally to the distal cone section 28 a, with exceptions notedherein. Referring to FIG. 3, the proximal cone section 28 b has distaland proximal ends 36 a, 36 b, a length L2 extending between the distaland proximal ends, and an exterior surface 40 having a generally conical(e.g., frustoconical) shape and a circumference or periphery (i.e., anouter dimension) and an outer diameter (i.e., an outer cross-sectionaldimension) tapering proximally toward the proximal end of the proximalcone section. An interior surface 44 of the proximal cone section 28 balso has a generally conical shape defining an inner circumference orperiphery (i.e., an inner dimension) and an inner diameter (i.e., aninner cross-sectional dimension) of the cone section that taperproximally toward its proximal end 36 b. As shown in FIG. 4, a wallthickness T3 of the proximal cone section 28 b between the interior andexterior surfaces 40, 44 generally increases toward the proximal end 36b thereof and the proximal waist section 26 b, such that the proximalcone section has a maximum wall thickness generally adjacent to theproximal waist section. Described another way, the wall thickness T3 ofthe proximal cone section 28 b tapers toward the distal end 36 a thereofand the body section 24.

In the illustrated embodiment, the structures of the distal cone section28 a have inverse relationships with the corresponding structures of theproximal cone section 28 b. Although not shown in detail in thedrawings, the distal cone section 28 a has proximal and distal ends, alength extending between the proximal and distal ends, and an exteriorsurface having a generally conical shape and defining an outercircumference or periphery (i.e., an outer dimension) and an outerdiameter (i.e., an outer cross-sectional dimension) of the cone sectionthat taper distally toward its proximal end. An interior surface of thedistal cone section also has a generally conical shape and defines aninner circumference or periphery (i.e., an inner dimension) and an innerdiameter (i.e., an inner cross-sectional dimension) of the cone sectionthat taper distally toward the distal end thereof. A thickness of thedistal cone section between the interior and exterior surfaces generallyincreases toward the distal end thereof and the distal waist section,such that the distal cone section has a maximum wall thickness generallyadjacent to the distal waist section. Described another way, thethickness of the distal cone section tapers toward the proximal endthereof and the body section.

Referring to FIGS. 1 and 2, at least one of the cone sections 28 a, 28 bcomprises grooves 50 to facilitate folding of the balloon 12. In theillustrated embodiment, each of the distal and proximal cone sections 28a, 28 b defines such grooves 50, as shown in FIGS. 1 and 2. In otherembodiments, only the distal cone section 28 a or only the proximal conesection 28 b may include the grooves 50. As seen in FIG. 6, the grooves50 are spaced apart from one another around the outer circumference(i.e., outer periphery) of the corresponding cone section 28 a, 28 b,and in the illustrated embodiment, the grooves 50 are uniformly spacedapart from one another. One or both cone sections 28 a, 28 b may includeany suitable number of grooves 50. In one example, the number of grooves50 is based, at least in part, on the outer diameter OD1 (i.e., outercross-sectional dimension) of the body portion 24 of the balloon 12. Forexample, one or both of the cone sections 28 a, 28 b includes one groove50 for every millimeter in outer diameter OD1 of the body section 24. Asan example, balloon including a body section having an outer diametermeasuring 8 mm will have 8 grooves (or at least 8 grooves) on one orboth of the cone sections. In one embodiment, the grooves 50 are formedduring blow molding, as explained below. In other embodiments, thegrooves 50 may be formed in other ways, such as by grinding or laserablation.

Referring to FIG. 5, a single groove 50 of the proximal cone section 28b is shown for illustrative purposes, with the understanding that theteachings of the illustrated groove apply equally to the other groovesof the cone section or sections. The groove 50 is defined by a bottomportion 54 and opposing side wall portions 56 extending from respectivesides of the bottom portion to the exterior surface 40 of the proximalcone section 28 b. The bottom portion 54 has opposite distal andproximal end sections 60 a, 60 b extending from corresponding proximaland distal ends of a central section 60 c of the bottom portion to theexterior surface 40 of the proximal cone section 28 b. In theillustrated embodiment, the distal and proximal end sections 60 a, 60 bof the bottom portion 54 are generally flat (see FIGS. 7 and 10), andthe central longitudinal section 60 c of the bottom portion is generallyarcuate in cross section (see FIGS. 8 and 9). As shown in FIG. 5, thedistal and proximal end sections 60 a, 60 b of the bottom portion 54extend at angles offset from a circumferential plane defined by thecircumference or periphery of the proximal cone section 28 b. The distaland proximal end sections 60 a, 60 b also extend in diverging directionsfrom the central section 60 c to the exterior surface 40 of the proximalcone section 28 b. As explained in more detail below, the flat distaland proximal end sections 60 a, 60 b and the arcuate central section 60c of the bottom portion 54 defining the groove 50 are formed bycorresponding portions of a mold to facilitate releasing of theblow-molded balloon from the mold.

Referring still to FIG. 5, the groove 50 has a length L3 extendinglengthwise of the proximal cone section 28 b between the proximal anddistal ends of the proximal cone section, and a depth D extending inwardfrom the exterior surface 40 of the proximal cone section. In theillustrated embodiment, the depth D of at least a portion of the groove50 (i.e., a central longitudinal portion that is partially defined bythe central longitudinal section 60 c of the bottom portion 54 definingthe groove) tapers toward the body section 24. That is, the depth D ofthe groove 50 tapers distally toward the distal end thereof and the bodysection 24. This tapering depth D is also evident from FIGS. 8 and 9,where the depth (indicated at D1) of the groove 50 taken at line 8-8 inFIG. 3 is greater than the depth (indicated at D2) of the groove takenat line 9-9 in FIG. 3. Inversely, the depth of at least a portion ofeach groove 50 of the distal cone section 28 a (i.e., the centrallongitudinal section 60 c) tapers proximally toward the proximal endthereof and the body section 24. Through this configuration, as shown inFIG. 5, a maximum depth D_(max) of each groove 50 is generally adjacentthe respective waist sections 26 b, 26 c, where the cone sections 28 a,28 b have maximum thicknesses, and a minimum depth D_(min) of eachgroove is generally adjacent the body section 24. It is believed thatthe maximum depths D_(max) of the grooves 50 at these locationsfacilitate folding and refolding of the balloon 12 at the locationsgenerally adjacent the respective waist sections 26 a, 26 b, where thecone sections 28 a, 28 b have maximum thicknesses. Thus, the grooves 50facilitate refolding of the balloon 12 after deflation to reduce thecross-sectional profile (e.g., the circumference) of the deflatedballoon. Facilitating re-folding of the balloon 12 into a lowcross-sectional profile decreases the pull-back force necessary to pullthe balloon back into the introducer sheath after treatment. It isunderstood that in other embodiments, the depths D of the grooves maynot taper lengthwise.

Referring to FIG. 7, the groove has a width W defined between theopposing side wall portions 56 and extending circumferentially of thecorresponding cone section. The width W of at least a longitudinalportion of the groove 50 tapers toward the body section 24. That is, thewidth W of at least a portion of each groove 50 of the proximal conesection 28 b tapers distally toward the distal end thereof and the bodysection 24, and the width of at least a portion of each groove of thedistal cone section 28 a tapers proximally toward the proximal endthereof and the body section. This tapering width W is also evident fromFIGS. 8 and 9, where the width (indicated at W1) of the groove 50 takenat line 8-8 in FIG. 3 is greater than the width (indicated at W2) of thegroove taken at line 9-9 in FIG. 3. Through this configuration, amaximum width of each groove 50 is generally adjacent the respectivewaist sections 26 a, 26 b. It is believed that the maximum widths of thegrooves 50 at these locations facilitate folding of the balloon 12 atthe locations generally adjacent the respective waist sections 26 a, 26b, where the cone sections 28 a, 28 b have maximum thicknesses. Thus,the grooves 50 facilitate refolding of the balloon 12 after deflation toreduce the cross-sectional profile (e.g., the circumference) of thedeflated balloon. Facilitating re-folding of the balloon 12 into a lowcross-sectional profile decreases the pull-back force necessary to pullthe balloon back into the introducer sheath after treatment. It isunderstood that in other embodiments, the widths W of the grooves maynot taper lengthwise or the widths may taper away from the body section.

As can be seen from FIGS. 8 and 9, in particular, the width W of atleast a portion of the groove 50 also tapers from adjacent the exteriorsurface 40 of the proximal cone section 28 b toward the bottom portion54 of the groove. This configuration facilitates releasing of theblow-molded balloon from the mold. It is understood that in otherembodiments, the widths W of the grooves may not taper depthwise.

In the illustrated embodiment, the cone sections 28 a, 28 b havecorresponding internal ribs 66 associated with the grooves 50 (e.g.,each groove has an associated rib). In other words, each of the dista;and proximal cone sections 28 a, 28 b includes ribs disposed atlocations on the interior surface of the corresponding cone sectiongenerally corresponding to locations of the grooves on the exteriorsurface of the corresponding cone section. The internal ribs 66 extendinward from the interior surface 44 of the corresponding cone section 28a, 28 b a radial distance R (see, e.g., FIG. 9). As explained in moredetail below, the dimensions of the ribs—including the lengths, widths,and radial distances R thereof—are based on the dimensions of mold ribsof the mold used to blow-mold the balloon and the thicknesses of thecone sections, which are based on the thickness of the parison and thedimensions (e.g., inner diameters) of the mold. In illustratedembodiment, the dimensions of each rib 66 are directly related to thedimensions of the corresponding groove 50. Thus, in the illustratedembodiment, the radial distance R of each rib 66 tapers toward the bodysection 24 and a width Wr of each rib (see, e.g., FIG. 9) taperslengthwise toward the body section and radially away from the interiorsurface 44. It is believed that the internal ribs 66 facilitate foldingof the balloon 12 at the locations generally adjacent the respectivewaist sections 26 a, 26 b, where the cone sections 28 a, 28 b havemaximum thicknesses. Thus, the ribs 66 facilitate refolding of theballoon 12 after deflation to reduce the cross-sectional profile (e.g.,the circumference) of the deflated balloon. Facilitating re-folding ofthe balloon 12 into a low cross-sectional profile decreases thepull-back force necessary to pull the balloon back into the introducersheath after treatment. In other embodiments, the cone sections may notinclude the internal ribs. As can be understood, in such an embodiment,the thicknesses of the cone sections are greater than the heights of thegroove-forming ribs of the mold.

Referring to FIG. 11, one embodiment of a mold for use in blow moldingthe medical balloon is illustrated schematically at reference numeral70. The mold 70 comprises a body molding section 72 defining a bodymolding cavity 74, and opposite proximal and distal cone-waist moldingsections, generally indicated at 76, at respective proximal and distalends of the body molding section and defining respective cone moldingcavities 78 and waist molding cavities 79. The body molding cavity 74 isgenerally cylindrical having a circumference that defines an outercircumference (i.e., an outer dimension) of the body section 24 of theblow molded balloon 12. The cone molding cavity 78 of the cone-waistmolding section 76 is used to form the corresponding proximal and distalballoon cones 28 a, 28 b during blow molding, and the waist moldingcavities 76 are used to form the corresponding proximal and distalballoon waists 26 a, 26 b during blow molding.

Referring to FIGS. 12 and 13, one of the cone-waist molding sections 76will be described with the understanding that the other cone-waistmolding section is identical, other than being positioned on an oppositeend of the body molding section 72. The waist molding cavity 79 isdefined by a generally cylindrical shaped interior surface 80 of thecone-waist molding section 76, although the interior surfaces definingthe waist molding cavities may have shapes other than cylindricalwithout departing from the scope of the present invention. The conemolding cavity 78 is defined by a generally conical shaped interiorsurface 80 of the corresponding cone-waist molding section 76, and aplurality of molding ribs 82 extending radially inward from the interiorsurface. As can be understood, the shape and sizes of the respectiveinterior surface 80 and molding ribs 82 of the illustrated cone-waistmolding section 76 are suitable for forming the cone sections 28 a, 28 bof the illustrated balloon 12 during a blow molding process. Forexample, the conical interior surface 80 of the cone-waist moldingsection 76 has a size and shape corresponding to the size and shape ofthe exterior surfaces 40 of the cone sections 28 a, 28 b of the balloon12. Moreover, the molding ribs 82 have sizes, shapes and locationscorresponding to the sizes, shapes and locations of the grooves 50 ofthe cone sections 28 a, 28 b of the balloon. For example, each moldingrib 82 has end portions 86 (see, e.g., FIG. 14) that are generally flatto facilitate releasing the balloon 12 from the mold. These end portions86 form the bottom end sections 60 a, 60 b of the bottom portions 54 ofthe grooves 50.

One example of blow molding the balloon 12 using the mold will now bedescribed. A parison or pre-form (not shown) is provided. The parisonmay comprise an extruded tube of polymeric material. In one example, theparison may have a uniform thickness along its length, although thethickness of the parison may vary along its length. The parison isinserted into the mold 70, heated to soften the polymer, and injectedwith a fluid (e.g., nitrogen gas) to pressurize the interior of theparison and expand the parison. Upon expansion of the heated parison,the parison takes on the shape of the mold to form the body section 24,the waist portions 26 a, 26 b, and the cone sections 28 a, 28 b, forexample. The parison is then cooled in the mold to form the balloon 12.Additional steps may be carried out during this process, including butnot limited to, a heat treating step and/or an axial stretching step.

The following non-limiting examples are provided to further illustrateembodiments of the present invention.

Test balloons having the illustrated grooves 50 and internal ribs 66formed on the distal and proximal cone sections 28 a, 28 b were formedusing a blow mold, similar to the illustrated blow mold 70. Controlballoons were also formed using the same process as the test balloonswith the grooves and ribs, except the grooves and ribs were omitted fromthe balloons. Other than the grooves and ribs, the two groups of balloonwere identical in shape, size and polymer. The inflated diameters of thebody sections of the test and control balloons measured 6 mm and thelengths of the test and control balloons measured 100 mm (i.e., 6×100 mmballoons). Each of the parisons or pre-forms used to form the balloonswas extruded nylon 12 polymer.

Each of the balloons from the test and control groups was tested for thepull-back force required to pull the balloon, in its deflatedconfiguration, back into a distal end of an introducer sheath. Each ofthe balloons from the test and control groups was also tested for there-insertion force required to re-insert the deflated balloon into theintroducer sheath. Each of these forces was determined using anapparatus suitable for measuring such forces. The overall results of thepull-back force test are shown in the chart provided in FIG. 15. FIG. 16shows the results of the pull-back force with outliers removed. Theoverall results of the re-insertion force test are shown in the chartprovided in FIG. 17.

As can be seen from FIGS. 15-17, both the pull-back force and there-insertion force for the test balloon was significantly less than thecontrol balloon, showing that the grooves 50 and/or the ribs 66contributed to the reduced pull-back and re-insertion force. In oneexample, the pull-back force of the balloon may measure from about 1.93lbs (8.59 N) to about 1.50 lbs (6.67 N).

Referring to FIG. 18, another embodiment of a medical balloon for amedical device is generally indicated at reference numeral 112 in FIG.18. The medical balloon 112 has a length L1′ and comprises a balloonbody section 124; opposite distal and proximal waist sections 126 a, 126b, respectively, at opposite longitudinal ends of the balloon; andopposite distal and proximal cone sections, generally indicated at 128a, 128 b, respectively, at corresponding distal and proximal ends of thebody section intermediate the body section and the corresponding distaland proximal waist sections. It is understood that the balloon 112 mayhave other sections, structures, and/or components without departingfrom the scope of the present invention. The balloon 112 may be formedfrom a polymer material, including, but not limited to, a thermoplasticpolymer or a thermoplastic elastomer polymer.

The body section 124 interconnects and is disposed between the distaland proximal cone sections 128 a, 128 b. In the illustrated embodiment,the body section 124 is generally tubular defining a portion of theinterior chamber 114 for receiving fluid to expand an outercircumference (i.e., an outer dimension) of the body section. Referringto FIG. 19, the body section 124 has an expanded inner diameter ID1′(i.e., an inner cross-sectional dimension) defined by an interiorsurface 130 of the balloon 112, an expanded outer diameter OD1′, and athickness T1′ that may be generally uniform along its length L1′. Thebody section 124 may have other shapes and dimensions without departingfrom the scope of the present invention.

The distal and proximal waist sections 126 a, 126 b are generallytubular and, in the illustrated embodiment, are configured to receive acatheter body (not shown) therein. Referring to FIG. 19, each waistsection 126 a, 126 b has an outer diameter OD2′ less than the outerdiameter OD1′ of the body section 124. Thicknesses T2′ of the waistsections 126 a, 126 b may be greater than the thickness T1′ of the bodysection 124. It is understood that the waist sections 126 a, 126 b maybe omitted from the balloon 112 without departing from the scope of thepresent invention.

In general, the distal and proximal cone sections 128 ab, 128 b aremirror images of one another. For purposes of this disclosure, theproximal cone section 128 b is shown in detail in the drawings, with theunderstanding that the teachings relating to the proximal cone sectionapply equally to the distal cone section 128 a, with exceptions notedherein. Referring to FIG. 19, the proximal cone section 128 b has distaland proximal ends 136 a, 136 b, a length L2′ extending between thedistal and proximal ends, and an exterior surface 140 having a generallyconical (e.g., frustoconical) shape and a circumference or periphery(i.e., an outer dimension) and an outer diameter (i.e., an outercross-sectional dimension) tapering proximally toward the proximal endof the proximal cone section. An interior surface 144 (FIG. 20) of theproximal cone section 128 b also has a generally conical shape definingan inner circumference or periphery (i.e., an inner dimension) and aninner diameter (i.e., an inner cross-sectional dimension) of the conesection that taper proximally toward its proximal end 136 b.

In the illustrated embodiment, the structures of the distal cone section128 a have inverse relationships with the corresponding structures ofthe proximal cone section 128 b. Although not shown in detail in thedrawings, the distal cone section 128 a has distal and proximal ends, alength extending between the distal and proximal ends, and an exteriorsurface having a generally conical shape and defining an outercircumference or periphery (i.e., an outer dimension) and an outerdiameter (i.e., an outer cross-sectional dimension) of the cone sectionthat taper distally toward its distal end. An interior surface of thedistal cone section also has a generally conical shape and defines aninner circumference or periphery (i.e., an inner dimension) and an innerdiameter (i.e., an inner cross-sectional dimension) of the cone sectionthat taper distally toward the distal end thereof.

Referring to FIG. 18, at least one of the cone sections 128 a, 128 bcomprises pleats 149 to facilitate folding of the balloon 112. In theillustrated embodiment, each of the distal and proximal cone sections128 a, 128 b defines such pleats 149, as shown in FIG. 18. In otherembodiments, only the distal cone section 128 a or only the proximalsection 128 b may include the pleats 149. Alternating outer and innerfold lines 149 a, 149 b are spaced circumferentially around the conesections 128 a, 128 b. Referring to FIG. 19, the outer fold lines 149 adefine outer most portions of the exterior surface 140 of the proximalcone section 128 and the inner fold lines 149 b define inner mostportions of the exterior surface. The outer and inner fold lines 149 a,149 b extend along the length L2′ of the proximal cone section 128 bbetween the body section 124 and the proximal waist section 126 b.Referring to FIGS. 19, 21 and 22, the outer diameter of each of theproximal and distal cone sections 128 a, 128 b at locations adjacent thecorresponding one of the proximal and distal waist sections 126 a, 126 bdefines triangular shapes 151 spaced around the circumference of said atleast one of the proximal and distal cone sections. Each of thetriangular shapes 151 has an apex 152 spaced apart from and disposedbetween the body section 124 and the corresponding one of the proximaland distal waist sections 126 a, 126 b. The apex 152 of each of thetriangular shapes intersecting a corresponding one of the outer foldlines 149 a. Each pleat 149 includes adjacent side walls 156 joined atthe corresponding inner fold line 149 b; the side walls 156 extend awayfrom one another to adjacent respective outer fold lines 149 a. Exteriorsurfaces of the adjacent side walls 156 are in generally opposingrelationship with respect to one another, while interior surfaces of theadjacent side walls face away from one another. The pleats 149 arejuxtaposed (i.e. side-to-side) and define a plurality of side-by-sidegrooves 150 in the cone section 128 a, 128 b. As such the cone sections128 a, 128 b shown in the illustrated embodiment generally have anaccordion pleat configuration. However, other pleat configurations areenvisioned.

As seen in FIGS. 19 and 21, the grooves 150 are spaced around the outercircumference (i.e., outer periphery) of the corresponding cone section128 a, 128 b, and in the illustrated embodiment, the grooves 150 areuniformly spaced around the outer circumference. Each groove 150includes a central section 160 c and opposite distal and proximal endsections 160 a, 160 b. One or both cone sections 128 a, 128 b mayinclude any suitable number of grooves 150. In one example, the numberof grooves 150 is based, at least in part, on the outer diameter OD1′(i.e., outer cross-sectional dimension) of the body portion 124 of theballoon 112 and the size and/or configuration of the pleats 149. Forexample, one or both of the cone sections 128 a, 128 b includes 2-3grooves 150 for every millimeter in outer diameter OD1′ of the bodysection 124. As an example, a balloon including a body section having anouter diameter measuring 8 mm will have about 20 grooves on one or bothof the cone sections. In one embodiment, the pleats 149 are formedduring blow molding, as explained below. In other embodiments, thepleats 149 may be formed in other ways, such as by grinding or laserablation.

Referring to FIG. 20, a single groove 150 of the proximal cone section128 b is shown for illustrative purposes, with the understanding thatthe teachings of the illustrated groove apply equally to the othergrooves of the cone section or sections. The groove 150 has a length L3′extending lengthwise of the proximal cone section 128 b between thedistal and proximal ends of the proximal cone section, and a depth D′extending inward from the exterior surface 140 of the proximal conesection. In the illustrated embodiment, the depth D′ of at least aportion of the groove 150 tapers away from the central section 160 c ofthe groove. That is, the depth D′ of the groove 150 tapers proximallyand distally away from the central section 160 c. Similar, the depth ofat least a portion of each groove 150 of the distal cone section 128 atapers proximally and distally away from the central section of eachgroove. Through this configuration, as shown in FIG. 20, a maximum depthD_(max)′ of each groove 150 is generally at the central section 160 c ofthe groove 150. It is believed that the maximum depths D_(max)′ of thegrooves 150 at these locations facilitate folding and refolding of theballoon 112 at the locations generally where the cone sections 128 a,128 b have maximum thicknesses. Thus, the grooves 150 facilitaterefolding of the balloon 112 after deflation to reduce thecross-sectional profile (e.g., the circumference) of the deflatedballoon. Facilitating re-folding of the balloon 112 into a lowcross-sectional profile decreases the pull-back force necessary to pullthe balloon back into the introducer sheath after treatment. Throughthis configuration, also shown in FIG. 20, minimum depths D_(min)′ ofeach groove 150 are located at the distal and proximal end sections 160a, 160 b of each groove. The minimum depths D_(min)′ at the distal andproximal end sections 160 a, 160 b produce smooth transitions betweenthe proximal cone section 128 b and the proximal waist section 126 b atthe proximal end section, and the proximal cone section and the bodysection 124 at the distal end section. The smooth transitions removepoints of weakness that could be present with abrupt transitions. Thiscan improve the overall strength of the balloon 112. It is understoodthat in other embodiments, the depths D′ of the pleats may not taperlengthwise.

Referring to FIG. 22, the groove 150 has a width W′ defined betweenadjacent outer fold lines 149 a and extending circumferentially of thecorresponding cone section. The width W′ of at least a longitudinalportion of the groove 150 tapers away from the body section 124. Thatis, the width W′ of at least a portion of each groove 150 of theproximal cone section 128 b tapers proximally away from the distal endthereof and the body section 124, and the width of at least a portion ofeach groove of the distal cone section 128 a tapers distally away fromthe proximal end thereof and the body section. This tapering width W′ isalso evident from FIGS. 23 and 24, where the width (indicated at W1′) ofthe groove 150 taken at line 23-23 in FIG. 19 is less than the width(indicated at W2′) of the groove taken at line 24-24 in FIG. 19. It isunderstood that in other embodiments, the widths W′ of the grooves maynot taper lengthwise or the widths may taper toward the body section.

As can be seen from FIGS. 22-26, in particular, the width W′ of at leasta portion of the groove 150 also tapers along the depth of the groove,i.e., from adjacent the outer fold lines 149 a of the proximal conesection 128 b toward the inner fold line 149 b of the groove. Thisconfiguration gives the groove 150 a triangular cross section andfacilitates releasing of the blow-molded balloon from the mold. It isunderstood that in other embodiments, the widths W′ of the grooves maynot taper depthwise.

In the illustrated embodiment, the cone sections 128 a, 128 b havecorresponding internal ridges or ribs 166 (FIG. 20) associated with thegrooves 150 (e.g., each groove has an associated rib) and defined by thepleats 149. In other words, each of the proximal and distal conesections 128 a, 128 b includes ribs 166 disposed at locations on theinterior surface of the corresponding cone section generallycorresponding to locations of the grooves 150 on the exterior surface ofthe corresponding cone section. The internal ribs 166 extend inward fromthe interior surface 144 of the corresponding cone section 128 a, 128 b.The dimensions of the ribs 166—including the lengths, widths, and radialdistances' thereof—are based on the dimensions of mold ribs of the moldused to blow-mold the balloon and the thicknesses of the cone sections,which are based on the thickness of the parison and the dimensions(e.g., inner diameters) of the mold. In illustrated embodiment, thedimensions of each rib 166 are directly related to the dimensions of thecorresponding groove 150. It is believed that the internal ribs 166facilitate folding of the balloon 112. Thus, the ribs 166 facilitaterefolding of the balloon 112 after deflation to reduce thecross-sectional profile (e.g., the circumference) of the deflatedballoon. Facilitating re-folding of the balloon 112 into a lowcross-sectional profile decreases the pull-back force necessary to pullthe balloon back into the introducer sheath after treatment. In otherembodiments, the cone sections may not include the internal ridges orribs. As can be understood, in such an embodiment, the thicknesses ofthe cone sections are greater than the heights of the groove-formingribs of the mold.

Referring to FIG. 26, an embodiment of a mold for use in blow moldingthe medical balloon 112 is illustrated schematically at referencenumeral 170. The mold 170 comprises a body molding section 172 defininga body molding cavity 174, and opposite proximal and distal cone-waistmolding sections, generally indicated at 176, at respective proximal anddistal ends of the body molding section and defining respective conemolding cavities 178 and waist molding cavities 179 (FIG. 28). The bodymolding cavity 174 is generally cylindrical having a circumference thatdefines an outer circumference (i.e., an outer dimension) of the bodysection 124 of the blow molded balloon 112. The cone molding cavity 178of the cone-waist molding section 176 is used to form the correspondingdistal and proximal balloon cones 128 a, 128 b during blow molding, andthe waist molding cavities 176 are used to form the corresponding distaland proximal balloon waists 126 a, 126 b during blow molding.

Referring to FIGS. 27-29, one of the cone-waist molding sections 176will be described with the understanding that the other cone-waistmolding section is identical, other than being positioned on an oppositeend of the body molding section 172. The waist molding cavity 179 isdefined by a generally cylindrical shaped interior surface 180 of thecone-waist molding section 176, although the interior surfaces definingthe waist molding cavities may have shapes other than cylindricalwithout departing from the scope of the present invention. The conemolding cavity 178 is defined by a generally conical shaped interiorsurface 181 of the corresponding cone-waist molding section 176, and aplurality of molding ribs 182 extending radially inward from theinterior surface. As can be understood, the shape and sizes of therespective interior surface 181 and molding ribs 182 of the illustratedcone-waist molding section 176 are suitable for forming the conesections 128 a, 128 b of the illustrated balloon 112 during a blowmolding process. For example, the conical interior surface 181 of thecone-waist molding section 176 has a size and shape corresponding to thesize and shape of the exterior surfaces 140 of the cone sections 128 a,128 b of the balloon 112. Moreover, the molding ribs 182 have sizes,shapes and locations corresponding to the sizes, shapes and locations ofthe grooves 150 of the cone sections 128 a, 128 b of the balloon.

Referring to FIGS. 30 and 31, another embodiment of a medical balloonfor a balloon catheter is generally indicated at reference numeral 212.Unless otherwise specifically indicated below, the medical balloon issubstantially similar to the first medical balloon 12 described above.Like the first medical balloon 12, the medical balloon 212 has a lengthand comprises a balloon body section 224; opposite proximal and distalwaist sections 226 a, 226 b, respectively, at opposite longitudinal endsof the balloon; and opposite proximal and distal cone sections,generally indicated at 228 a, 228 b, respectively, at correspondingproximal and distal ends of the body section intermediate the bodysection and the corresponding proximal and distal waist sections. Alsolike the first balloon 12, the body section 224, waist sections 226 a,226 b, and cone sections 228 a, 228 b of the present balloon 212 may beintegrally formed during a blow molding process to form the balloon as aone-piece construction. It is understood that the balloon 212 may haveother sections, structures, and/or components without departing from thescope of the present invention.

As shown best in FIG. 31, the main difference between this medicalballoon 212 and the first medical balloon 12 is that grooves 250 of thepresent balloon—which may be similar or identical in shape, size and/ornumber as the grooves 50—extend from the respective proximal and distalcone sections 228 a, 228 b to the body section 224. In particular, eachgroove 250 is a continuous groove, such that one longitudinal end of thegroove is located in the corresponding cone section 228 a, 228 b, andthe other longitudinal end of the groove is located in the body section224. In another embodiment, respective grooves formed in the bodysection 224 (not shown) may connect with the longitudinal ends of thecorresponding grooves 250 located in the body section.

Referring to FIG. 32, a suitable one of cone-waist molding sections 276for forming the balloon 212 in a manner similar to that described abovewith respect to the balloon 12 will be described with the understandingthat the other cone-waist molding section is identical, other than beingpositioned on an opposite end of a body molding section (not shown).Unless otherwise specifically indicated below, the cone-waist moldingsection 276 may be substantially similar to the first cone-waist moldingsection 76. The main difference between present cone-waist moldingsection 276 and the first cone-waist molding section 76 is that thepresent cone-waist molding section includes a partial body moldingcavity 277 for molding a portion of the body section 224 that includescorresponding longitudinal end portions of the grooves 250. A pluralityof molding ribs 282 extend from a waist molding cavity 278 to thepartial body molding cavity 277 for forming the waist section 226 b, thecone section 228 b, the aforementioned portion of the body section 224,and the grooves 250. It is understood that the balloon 212 may be formedin other ways without departing from the scope of the present invention.

Having described the invention in detail, it will be apparent thatmodifications and variations are possible without departing from thescope of the invention defined in the appended claims.

When introducing elements of the present invention or the preferredembodiment(s) thereof, the articles “a”, “an”, “the” and “said” areintended to mean that there are one or more of the elements. The terms“comprising”, “including” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements.

As various changes could be made in the above constructions, products,and methods without departing from the scope of the invention, it isintended that all matter contained in the above description and shown inthe accompanying drawings shall be interpreted as illustrative and notin a limiting sense.

What is claimed is:
 1. A balloon for a balloon catheter comprising: aproximal cone section having proximal and distal ends, a lengthextending between the proximal and distal ends, and an exterior surfacehaving a generally conical shape, an outer diameter, and a circumferencetapering proximally toward the proximal end of the proximal conesection; a distal cone section having proximal and distal ends, a lengthextending between the proximal and distal ends, and an exterior surfacehaving a generally conical shape, an outer diameter, and a circumferencetapering distally toward the distal end of the distal cone section; aballoon body section extending between and interconnecting the distalend of the proximal cone section and the proximal end of the distal conesection, the proximal and distal cone sections and the balloon bodysection defining an interior chamber configured to receive fluid toexpand the balloon from a non-expanded state to an expanded state, aproximal waist section extending proximally from the proximal end of theproximal cone section; and a distal waist section extending distallyfrom the distal end of the distal cone section; wherein at least one ofthe proximal and distal cone sections defines pleats spaced around thecircumference of said at least one of the proximal and distal conesections, the pleats defining grooves each having a length extendinggenerally lengthwise of said at least one of the proximal and distalcone sections, a depth extending inward from the exterior surface ofsaid at least one of the proximal and distal cone sections to a bottomof the groove, and a width extending circumferentially of said at leastone of the proximal and distal cone sections, wherein each pleatincludes an inner fold line at the bottom of the groove, a pair ofadjacent outer fold lines at the outer diameter of said at least one ofthe proximal and distal cone sections, and a pair of side wallsextending from the inner fold line away from one another to therespective one of the pair of adjacent outer fold lines, wherein theouter diameter of said at least one of the proximal and distal conesections at locations adjacent the corresponding one of the proximal anddistal waist sections defines triangular shapes spaced around thecircumference of said at least one of the proximal and distal conesections, wherein each of the triangular shapes has an apex intersectingone of the outer fold lines of the pair of adjacent outer fold lines ofthe corresponding pleat of said at least one of the proximal and distalcone sections, and the apex being spaced apart from and disposed betweenthe balloon body section and the corresponding one of the proximal anddistal waist sections.
 2. The balloon set forth in claim 1, wherein thewidth of at least a portion of each groove tapers away from the balloonbody section.
 3. The balloon set forth in claim 2, wherein the depth ofat least a portion of each groove tapers away from the balloon bodysection.
 4. The balloon set forth in claim 2, wherein the width of eachgroove tapers from adjacent the exterior surface of said at least one ofthe proximal and distal cone sections toward the bottom of the groove.5. The balloon set forth in claim 4, wherein each of the grooves has atriangular cross section.
 6. The balloon set forth in claim 1, whereinsaid at least one of the proximal and distal cone sections includes aplurality of ridges defined by the pleats and extending inward from aninterior surface of said at least one of the proximal and distal conesections.
 7. The balloon set forth in claim 1, in combination with acatheter, wherein the balloon is secured to the catheter.
 8. The balloonset forth in claim 1, wherein the proximal cone section defines at leastsome of the pleats.
 9. The balloon set forth in claim 1, wherein thedistal cone section defines at least some of the pleats.
 10. The balloonset forth in claim 1, wherein minimum depths of each groove are locatedgenerally at proximal and distal end sections of each groove.
 11. Theballoon set forth in claim 1, wherein the depth of at least a portion ofeach groove tapers away from the balloon body section.
 12. The balloonset forth in claim 1, wherein each groove has a distal end section, aproximal end section, and a central section between the distal andproximal end sections, wherein the depth of each groove at the proximalend section tapers from adjacent the central section toward the balloonbody section.
 13. The balloon set forth in claim 12, wherein the depthof each groove at the distal end section tapers from adjacent thecentral section away from the balloon body section.
 14. The balloon setforth in claim 1, wherein each groove has a distal end section, aproximal end section, and a central section between the distal andproximal end sections, wherein the depth of each groove at the centralsection is defines the maximum depth of the respective groove.
 15. Theballoon set forth in claim 14, wherein the depth of each groove at theproximal end section tapers from adjacent the central section toward theballoon body section.
 16. The balloon set forth in claim 1, wherein thepleats extend to the balloon body section.
 17. The balloon set forth inclaim 1, wherein the pleats are disposed side-by-side around thecircumference of said at least one of the proximal and distal conesections.